3,10,13,28,31,__

• 54
  
  Make into pairs
  (3 , 10) , (13 , 28) , (31 , x)
  
  3 = 2^2 - 1
  10 = 3^2 + 1
  
  13 = 4^2 - 3
  28 = 5^2 + 3
  
  31 = 6^2 - 5
  =>x = 7^2 + 5 = 54
  
• 11 years agoHelpfull: Yes(7) No(0)
• ans=54.....3=2*2+1
  10=3*3+1
  13=4*4-3
  28=5*5+3
  31=6*6-5
  54=7*7+5
• 11 years agoHelpfull: Yes(0) No(0)